Pump rebuilts

Well-Known Member

So I'm rebuilding the pumps on my 717 engines on my 97 Sea-Doo speedster. I have it all assembled correctly, I know there's no issues with that.

My question is how tight do I tighten the impeller to the pump shaft. When I tighten it down snug, I cannot spin the impeller freely by hand. I have to give it a little bit of force but it will spend just doesn't spend freely.

Is that right?

Or do I need to loosen it up a little so the impeller spins freely? When I say freely.. Im referring to how freely a fan blade spins when off on say a desktop fan.

Moderator

You could have already crushed your thrust bearing too as they can slip into the shaft oil groove and get pinched causing the symptoms you have. Pull it back out and check.

Since you don’t know the torque I assume you didn’t use the manual so you also didn’t set the bearing depth correctly. You can’t just push the bearings in as they have to be set to an exact depth per the manual.

Well-Known Member

Ok..so I took it all apart. The thrust bearings are fine and in tack. So I tried to just put the impeller in there, with no shaft. And thats my issue. Its so tight it must be hitting or something. I can't spin it..is it possible the wear ring is the wrong size or something?

Member

I have a set of brass pumps and a set of plastic pumps. Though they are supposed to use the same 140mm wear ring the brass pumps are actually slightly smaller in diameter. I can slide a new (oem) wear ring into my plastic pumps but it takes some serious force to get them into the brass pumps. Anyway because of the smaller size the wear ring actually interferes with the impeller on the brass pumps. I have to hand turn them with a wrench to abraid the wear ring material away until the impeller spins freely.

Well-Known Member

I have a set of brass pumps and a set of plastic pumps. Though they are supposed to use the same 140mm wear ring the brass pumps are actually slightly smaller in diameter. I can slide a new (oem) wear ring into my plastic pumps but it takes some serious force to get them into the brass pumps. Anyway because of the smaller size the wear ring actually interferes with the impeller on the brass pumps. I have to hand turn them with a wrench to abraid the wear ring material away until the impeller spins freely.

This was sooo helpful. Thanks! I dont notice the blade touching the wear ring. If it is, its so slightly..its not notice. But I also read/heard its because it was too tight to the shaft. Either way..I heard to just throw it on the engine..and the rpm's from it will work it out.

Did it free up enough for you by just spinning it? It seams to be be tight in general. If I put it in the plastic ones (not screwed to the shaft and spin it, it spins freely. If I do the same on the bronze, remember without screwing it to the shaft, it still spins hard.

Member

Well on my plastic pumps I just stick them on the boat, back it in the water, and start it. Shaves a small amount the material away.

On my brass pumps the housing bore is .020 in smaller that's how much material needs to comes off of the wear ring. When I put them on the boat it's locked up and won't even turn over. So with the pump out I use a ratchet to turn the impeller with a bit of lube. Just crank away until the impeller spins. It takes awhile..........if yours are as bad as mine. One rebuild we used a drill to spin it. And then the pumps take a couple runs the free up completely once on the boat. What makes it worth the effort is you literally have perfect wear ring clearance.